Diverging diamonds evidently are becoming a traffic engineer’s best friend.
The Ohio Department of Transportation has set up an online open house as it contemplates altering Airport Highway’s interchange on I-475/U.S. 23 in Springfield Township with an eye toward reducing crashes and congestion there.
But its district planners in Bowling Green have already stated what their preference is for such a project: crossing Airport’s lanes over to the left in the same sort of diverging-diamond interchange layout ODOT contractors built several years ago at the same freeway’s State Rt. 25 interchange in Perrysburg.
According to a summary of the “virtual open house” that began Monday, Airport Highway — which carries State Rt. 2 through the area — had 576 crashes between McCord and Holland-Sylvania roads between 2017 and 2019. That ranked it No. 1 on ODOT’s Highway Safety Improvement Improvement Program list of “suburban nonfreeway segments,” with two-thirds of the crashes rear-enders and 30 percent causing injuries.
Materials are available to view on the feasibility study’s web page, accessible under “Featured Projects” on the ODOT District 2 website . The formal public comment period ends June 16.
No construction funding has been allocated for the interchange, and alternative designs remain on the table. The earliest possible year for construction is 2026, according to ODOT’s online materials.
“The goal of the feasibility study is to identify a preferred alternative which will improve safety and reduce congestion at the interchange,” said Kelsie Hoagland, a spokesman at the Bowling Green office. “...Once a preferred alternative is identified, we will pursue applying for funding.”
ODOT is holding only a virtual open-house for this proposal, she said, because none of the options studied for the Airport interchange would require condemning any land, whereas the Perrysburg interchange designs include some land acquisition.
The existing Airport interchange has ample land to accommodate any of the alternatives considered in a preliminary feasibility study, she said. Construction of a multi-use path 10 feet wide along Airport Highway’s north side would require some temporary right-of-way.
Along with revising the interchange and creating the path, ODOT intends to reconfigure traffic on Spring Meadows Drive to create two left-turn lanes, which will allow more vehicles headed to I-475 to exit the Spring Meadows Place shopping area during each green light. The current right-turn lane would become marked for straight-across traffic as well.
A separate ODOT plan to place a median divider on McCord just north of its intersection with Airport — intended to reduce congestion and crashes associated with left turns at Centers and Spring Valley drives and a Buckeye Broadband driveway just north of Airport — has been delayed after nobody bid on a construction contract advertised this spring, said Kacey Young, ODOT’s district capital programs administrator.
The McCord work “is going to be packaged with another project, and will likely occur in 2023,” Ms. Young said. “The goal is to have the work occur while school is out during summer 2023.”
Nearby merchants have protested that shutting off left turns onto Spring Valley, in particular, would discourage customers by forcing them to take longer routes and add traffic in front of Springfield High School.
Airport in the Spring Meadows area has long been one of metro Toledo’s busiest roadways and congestion hot spots.
Construction of its median between I-475 and Holloway Road two decades ago eliminated crashes and delays related to shoppers turning left into and out of commercial driveways but was similarly controversial among some merchants. At that time, the ramp from southbound I-475/U.S. 23 to westbound Airport was modified to replace its high-speed merge onto Airport with a traffic light.
The newly proposed interchange designs realign all of the ramps there and eliminate two cloverleaves.
Besides examining a diverging diamond, ODOT planners looked at two other options for the Airport Highway ramp intersections: a “tight urban diamond” that is more traditional and a double-roundabout layout similar to one completed last year at a new I-475/U.S. 23 interchange for Dorr Street several miles to the north. But according to the state’s online presentation, they are disfavored because they provide “minimal safety improvements” and the roundabout option would also have “failing operations.”
The multi-use path will be built along Airport’s north side between West Mall Drive and Holland-Sylvania regardless of which ramp layout is ultimately chosen, ODOT said.
Construction of metro Toledo’s second diverging diamond is slated to begin later this year on U.S. 20A as part of an expansion of I-475’s Salisbury/Dussel interchange, and a proposal for a third at the U.S. 20/23 interchange on I-75 in Perrysburg was introduced to the public in late March during a live open-house meeting at Perrysburg Junior High School.
A diverging diamond layout works by crossing opposing traffic from the standard right-hand side of the roadway to the left at a freeway interchange between the ramp intersections on either side of the freeway. Doing that allows left turns to and from the freeway ramps to be made without crossing opposing traffic lanes, which reduces both the number of potential “conflict points” at the interchange and the number of traffic-signal phases required to handle all traffic movements.
Although the left-hand running discomforts some drivers, the diverging diamond on Route 25 has been generally well-received since its completion several years ago.
Less popular has been the “single-point urban interchange” design ODOT used when it recently rebuilt the Central Avenue interchange on I-475/U.S. 23 in Sylvania Township, but ODOT did not even consider that design for the Airport interchange.
First Published May 21, 2022, 6:59 p.m.